NURSING ANM AND GNM

NURSING EXAM QUESTIONS

BIOCHEMISTRY

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
At 40 degrees Celsius, your biological enzymes will ____
A
Functional optimally
B
Denature
C
Wait until the temp. increases
D
Wait until the temp. decreases
Explanation: 

Detailed explanation-1: -Optimum temperature is the temperature at which enzyme activity is maximum. In humans, this temperature is 37.5oC that is same as the normal body temperature. A rise in temperature above 40oC results in denaturation of the proteins of enzyme.

Detailed explanation-2: -Because most animal enzymes rapidly become denatured at temperatures above 40°C, most enzyme determinations are carried out somewhat below that temperature. Over a period of time, enzymes will be deactivated at even moderate temperatures. Storage of enzymes at 5°C or below is generally the most suitable.

Detailed explanation-3: -This optimal temperature is usually around human body temperature (37.5 oC) for the enzymes in human cells. Above this temperature the enzyme structure begins to break down (denature) since at higher temperatures intra-and intermolecular bonds are broken as the enzyme molecules gain even more kinetic energy.

Detailed explanation-4: -While higher temperatures do increase the activity of enzymes and the rate of reactions, enzymes are still proteins, and as with all proteins, temperatures above 104 degrees Fahrenheit, 40 degrees Celsius, will start to break them down.

Detailed explanation-5: -Because enzymes are proteins, they are denatured by heat. Therefore, at higher temperatures (over about 55°C in the graph below) there is a rapid loss of activity as the protein suffers irreversible denaturation.

There is 1 question to complete.